As is well known structural concrete castings are produced with the use of shutterings of timber planks which are held together by nailing plank to plank or by auxiliary connecting members, such as wooden bars, fillets and the like.
The work connected with preparation of the shuttering for a building or any other structure, or part of it, is quite considerable and, above all, time consuming.
It has also been suggested to use metal sheets and to build up shutterings from the latter. However, these metal members have been used only in cases where standardized, mostly prefabricated, building elements were cast. Quite complicated and costly connecting members for such individual metal planks have been suggested which only in the case of use for prefabricated, standardized elements do not materially affect the cost of the building structure.